Jet lag may make it hard for you to fall asleep, stay asleep, or stay awake during the day. Lack of sleep can make you feel tired or tense and make it hard for you to focus. You may feel weak, or you may lose your appetite. You may not be able to have a bowel movement (constipation), or you may have diarrhea.

When you fly east, the number of days it takes to recover from jet lag will be about two-thirds the number of time zones you cross. For example, if you cross six time zones, it will take you about 4 days to get back to normal.

When you fly west, the number of days to recover equals about half the number of time zones. So if you cross six time zones, it will take you 3 days to recover.

Jet lag can happen to anyone. Your age, fitness, health, and how often you fly don't make a difference in whether you get it.

Test Your Knowledge

Symptoms of jet lag include:

Having a hard time with falling asleep, staying asleep, or staying awake.

Feeling tired and tense and not being able to focus.

Not feeling like eating.

This answer is incorrect

Having sleep problems; feeling tired, tense, and unfocused; and not having an appetite are all symptoms of jet lag.

This answer is incorrect

Having sleep problems; feeling tired, tense, and unfocused; and not having an appetite are all symptoms of jet lag.

This answer is incorrect

Having sleep problems; feeling tired, tense, and unfocused; and not having an appetite are all symptoms of jet lag.

You may get jet lag when you fly across one or more time zones. This happens when you fly east to west or west to east. When you fly north to south or south to north, you don't cross time zones, so you don't get jet lag.

Crossing time zones disrupts your body's "biological clock," or 24-hour rhythms (circadian rhythms). You have symptoms because your biological clock has not adjusted to the new time zone. Your body thinks that you're still in your old time zone.

For example, if you fly from Chicago to Rome, you cross seven time zones. This means that Rome is 7 hours ahead of Chicago. When you land in Rome at 6:00 in the morning, your body thinks it's still in Chicago at 11:00 the previous night. Your body wants to sleep, but in Rome the day is just starting.

Other things besides your wake/sleep cycle are affected. You may not be hungry at dinnertime in Rome, but you may be very hungry in the middle of the day. Your bowel movements may be on a different schedule than normal.

As your body adjusts to the time change, the symptoms go away.

Test Your Knowledge

You can get jet lag when you:

Take a long road trip.

Fly across one or more time zones.

Fly north or south.

This answer is incorrect

When you take a long road trip, you may cross time zones. But the time it takes to cross them allows your body to adjust. You get jet lag when you cross time zones quickly, as you do in an airplane. All the answers are correct.

This answer is correct

You can get jet lag when you fly across time zones. This happens when you fly east or west. All the answers are correct.

This answer is incorrect

You can get jet lag when you fly east or west across time zones. When you fly north or south, you don't cross time zones. All the answers are correct.

You can't cure jet lag, but you may be able to reduce the symptoms using the hormone supplement melatonin and sleeping pills. Other treatments besides medicines have not been studied or have been studied very little, but they may be worth trying.

Melatonin and sleeping pills

Melatonin is a hormone that your body makes. It regulates the cycle of sleeping and waking. Normally, melatonin levels begin to rise in the mid- to late evening, remain high for most of the night, and then go down early in the morning.

Taking melatonin may help "reset" your biological clock. Studies show that it has reduced the symptoms of jet lag for people flying both east and west.2

Suggestions about times and dosages vary among researchers who have studied melatonin. Doctors recommend that you:

Take melatonin after dark on the day you travel and after dark for a few days after you arrive at your destination.

Take melatonin in the evening for a few days before you fly if you will be flying east.

The safety and effectiveness of melatonin have not been thoroughly tested. Taking large doses of it may cause sleep disruption and daytime fatigue. If you have epilepsy or are taking blood thinners such as coumadin (Warfarin), talk to your doctor before you use melatonin.

The sleeping pills eszopiclone (Lunesta) and zolpidem (Ambien) have been studied for jet lag. They may help you sleep despite jet lag if you take them before bedtime after you arrive at your destination. You may have side effects of headaches, dizziness, confusion, and feeling sick to your stomach.

Other things to do

None of the things in the following lists have been proved to reduce jet lag, but some people find them helpful.

Before you go, and on the plane

Be well rested before you start to travel.

If you are flying east, go to bed 1 hour earlier each night for a few days before your trip. If you're flying west, go to bed 1 hour later each night instead. But if your trip will last 2 days or less, stay on your home time.

Set your watch to your new time zone as you start flying. If it's nighttime at your destination, try to sleep on the plane. Sleep masks, earplugs, and headphones may help. If it's daytime at your destination, try to stay awake.

On the plane, drink water to avoid dehydration. Avoid alcohol and drinks that contain caffeine.

When you arrive

Try to change your schedule to the new time as soon as you can. For example, if you arrive at 4 p.m., do your best to stay awake until your usual bedtime. Get up in the morning instead of sleeping late.

Think about light exposure. If you flew east, try to avoid bright light in the morning, and get light in the afternoon. To avoid light in the morning, stay indoors, such as by going to a museum. If you flew west, stay awake during daylight, and try to sleep after dark. This may help adjust your body clock and help your body make melatonin at the right time.

Caffeine may help you stay alert during the day after you arrive. But it also may make it harder to sleep at night.

If you have an important meeting or athletic event, try to arrive a few days early so your body can adjust to the new time zone.

Test Your Knowledge

To cure jet lag, you can use melatonin before or after you travel.

True

False

This answer is incorrect

Nothing has been proved to prevent or cure jet lag. Melatonin may help reduce symptoms.

This answer is correct

Nothing has been proved to prevent or cure jet lag. Melatonin may help reduce symptoms.

This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.